# Regular Expressions

## Sample expressions:

Regular Expressions
Function Regular Expression Will match Remarks
Fully qualified path (("?)[A-Z]:(\\[^:\\"\n\r]+)*\\?\2) Any local path May break on ampersands
Fully qualified path ("[A-Z]:(\\[^:\\"\n\r]+)*\\?"|[A-Z]:(\\[\w_-\.]+)*\\?) Any local path
Fully qualified path ("([A-Z]:|\\\\[\w_-\.]+\\[\w_-\.]+)(\\[^:\\"\n\r]+)*\\?"|([A-Z]:|\\\\[\w_-\.]+\\[\w_-\.]+)(\\[\w_-\.]+)*\\?) Any local or UNC path
Simple date ([0-9]{1,2}[-/][0-9]{1,2}[-/]([0-9]{2})?[0-9]{2}) Any date Will match 99/99/9999 or 00-00-00
Date (MM/DD/YYYY) ((0?[1-9]|1[0-2])/(0?[1-9]|[12][0-9]|3[01])/[12][0-9]{3}) Date in current or previous millennium Will match 2/31/2010
Date (DD-MM-YYYY) ((0?[1-9]|[12][0-9]|3[01])-(0?[1-9]|1[0-2])-[12][0-9]{3}) Date in current or previous millenium Will match 31-2-2010
Simple time ([0-9]{1,2}:[0-9]{2}(:[0-9]{2}(\.[0-9]+)?)?) Any time Will match 99:99:99.999
Time (24h) (([01]?[0-9]|2[0-3]):[0-5][0-9](:[0-5][0-9](\.[0-9]+)?)?) True time Will only match valid times in 24h notation, with seconds and fraction of seconds optional
Time (AM/PM) ((0?[0-9]|1[0-2]):[0-5][0-9](:[0-5][0-9](\.[0-9]+)?)? ?([AaPp][Mm]?)?) True time Will only match valid times in AM/PM notation, with seconds, fraction of seconds and AM/PM/A/P optional and case insensitive
E-mail address ([\w-\.]+\@([\w-]+\.)+[\da-zA-Z]{2,4}) Valid e-mail address Will also find a match even in invalid numerical top level domains; when an e-mail address is valid, it doesn't necessarily mean it exists.
Simple HTML tag (<[ˆ>]+>) Any tag in HTML code Will fail on <img src="fastforward.gif" alt=">>">
HTML tag with embedded text (<[ˆ>]+>([ˆ<]+<\/[ˆ>]+>)?) Single tag only or "tag set" including attributes Will also fail on <img src="fastforward.gif" alt=">>"> and on nested HTML tags, e.g. <b><i>text</i></b>
HTML tag with embedded text (<[ˆ>\"]+([ˆ\">]+=\"[ˆ\"]*\" *)*>([ˆ<]+<\/[ˆ>]+>)?) Single tag only or "tag set" including attributes Will fail on nested tags, e.g. <b><i>text</i></b> and doesn't detect incorrect tag sets, e.g. <b>text</i>
HTML tag with embedded text (<([ˆ\/\s>\"])+(\s+[ˆ\">]+=\"[ˆ\"]*\"\s*)*>(.+<\/\2>)?) Single tag only or "tag set" including attributes Does not detect improperly nested tags, e.g. <b><i>text</b></i>
Simple IP (v4) address (([0-9]{1,3}\.){3}[0-9]{1,3}) Any IP (v4) address Will match 999.999.999.999
IP (v4) address (([0-2]?[0-9]{1,2}\.){3}[0-2]?[0-9]{1,2}) Any IP (v4) address Will still match 299.299.299.299